A combination of Polyphor's investigational therapy balixafortide (POL6326) and Eisai's Halaven (eribulin) may prolong the survival of women with HER2-negative metastatic breast cancer, a Phase 1 trial shows. The findings were presented in the poster "Balixafortide (a CXCR4 antagonist) + eribulin in HER2-negative metastatic breast cancer (MBC): Survival outcomes of the phase I trial" (abstract #2606) at the recent 2019 American Society of Clinical Oncology (ASCO) Annual Meeting in Chicago. Balixafortide is a potent and selective inhibitor of CXCR4, a protein receptor that controls cancer and immune cell migration, tumor growth, survival, and metastasis (cancer's spread to other regions or organs). High levels of CXCR4 are normally associated with tumor aggressiveness and a poor prognosis. According to Polyphor, balixafortide is the only CXCR4 inhibitor currently in development as a combination therapy for breast cancer, and the most advanced CXCR4 blocker for other types of solid tumors. Halaven is a chemotherapy agent that prevents cancer cells from dividing and proliferating by interfering with internal components called microtubules. It is approved by the U.S.